Diestock



June 29, 1943. WALDQ 2,322,901

DIE swocx Filed Nov. 7, 1941 Y F I l 2 INVENTOR.

BY I a ATTORNEYS Patented June 2 9, 1943 -DIESTOCK John E. Waldo, Bridgeport, Conm, assignor to Armstrong Manufacturing (30.,

Bridgeport,

Conn., a corporation of Connecticut Application November 7, 1941, Serial No. 418,186

5' Claims.

My invention relates to new andv improved diestocks.

One of the objects of my invention is to provide an improved diestock, of the type which is used for forming a thread on articles of cylindrical shape, such as rods, pipes, bolts, etc.

Another object of my invention is to provide a diestock of this type, in which the respective dies or chasers are held fixed to the diestock, during the operation of cutting the thread.

Another object of my invention is to provide a diestock of extremely simple construction and which can be manufactured at minimum cost, by eliminating expensive machining operations as much as possible.

. Other objects of the invention will be stated in the annexed description and drawing, which illustrates preferred embodiments thereof.

Fig. 1 is a perspective view of the assembled device.

Fig. 2 is a plan view of the inner surface of the top plate. This surface is the bottom surface of the top plate, when said plate is held in the position illustrated in Fig. 1, in which the longitudinal axis of the diestock is vertical.

Fig. 3 is a perspective view of a die segment or chaser.

Fig. 4 is a perspective view of the diestock which is illustrated in Fig. 1, with the top plate and chasers removed. This figure also conventionally shows the usual non-ratchet collar which can be detachably clamped by means of the screw S to the lower part of the body of the diestock in order to turn the body of the diestock around its longitudinal axis, by. means of the handles H.

Fig. 5 is a'perspective view of a modified type of diestock, with the top plate removed. This illustrates the conventional multiple diestock, modified according to the invention.

It is well-known in this field to provide a diestock Which is turned about its longitudinal axis,

either continuously by a non-ratchet type of drive, or intermittently by a ratchet type of drive. It is also well-known to provide diestocks with radial grooves in which the chasers are located, and to provide said diestocks with clearance openings intermediate said radial grooves. 'Numerous devices have been suggested for holding the chasers fixed relative to the diestock, but such devices have required accurate and expensive machining, and such machining is reduced to a minimum according to my invention.

Fig. 1 illustrates a type of diestock which can be turned intermittently by means of a ratchet drive. The body I is provided with spaced teeth 2, which can. be engaged by the pawl of the ratchet collar. This ratchet collar and the ratchet drive of this type of diestook are not illustrated, as they are conventional.

Fig. 4 shows that the body I is provided with posts 3, which are arranged in pairs, so that radial grooves 4 are provided between the respective pairs of posts 3, in order to receive the chasers or die segments 5. The chasers 5 are of conventional construction and they have the usual recesses 5a.

Clearance openings 6 are provided between the respective pairs of posts 3, so that the chips or the like can fall freely out of the diestock. One of each pair of posts 3 is provided with a tapped opening 1, which can receive the shank of a clamping screw 8.

The top plate 9 is shaped wholly by stamping into the shape illustrated in Figs. 1 and 2, so as to eliminate all machining operations. The top plate 9 is provided with a central opening I0, and with a series of stamped and upwardly projecting lugs ll, thus forming stamped radial recesses [2 in the inner surface of said plate 9. Each recess I2 is provided with a lateral extension M, which is provided with a hole l5, through which the shank of the respective screw 8 can pass. The top portion of each chaser 5 projects into one of the recesses 12 and the radial side walls of the top portion of the chaser fit snugly in the respective recess 12, with the exception of the lateral extension M of said recess l2, and with the exceptionof the inner radial part of the chaser 5, which extends into opening Ill. The bottom portion of each chaser 5, namely, the axially inner edge of' each chaser 5, fits snugly against the bottom wall of the respective groove 4. The top portion of each chaser 5 projects above the top of the respective radial groove 4.

Each and every part of the plate 9 is therefore located at or wholly above the top of the body I.

When the device is assembled, the top portion of the butt end or lateral outer end of each chaser 5, abuts the lateral outer wall of the respective recess l2.

the shanks of the' clamping screws 8 engage the tapped recesses l of the respective posts 3, the respective chasers 5 are thus firmly clamp-ed and fixed by the plate 9 relative to the body I of the diestock. The radial outer movement of each chaser 5 is positively prevented byv the abutment of the top portion of the butt end 'respective different diameters.

spective radial recess I2.

By means of stamping, in one or more operations, it is possible to shape the recesses I2 with suflicient accuracy, so as to eliminate all the machining operations which would be required if the top holding plate had to be provided with lugs which extended into the respective radial grooves 4. Likewise, since the use of a ring of L-shape cross-section is eliminated, the clearance openings 6 are left perfectly clear and it is possibleeasily to shape the top plate 9 by stamping, either by a single stamping operation or by a plurality of stamping operations. The top and bottom walls of plate 9 are absolutely planar, save for its radial lugs or projections II and the corresponding radial recesses l2, thus facilitating the stamping operation or operations.

In the embodiment of Fig. 5, the diestock has a modified hollow body Ia, which is provided with projections or posts I6, between which radial grooves 4a are provided. These radlial grooves 4a have the same function as the radial grooves 4 of the first embodiment. Each alternate post or projection I6 is provided with a tapped recess la, which has the same function as the tapped recess I of the first embodiment.

The multiple diestock which is shown in Fig. 5,

.has three sets of grooves 4a. The grooves 4a in veach set are identical, or they may differ in width or depth or both in width and depth.

A bore or hollow C is provided, between the radial inner faces of each of the three sets of posts I6. The hollow body Ia has three bores or openings Pa, each of which is aligned with one of the bores C. Only one of these openings Pa is visible in Fig. 5. The bores Pa may be: of different size or the same size. A set of chasers can be located in one or more of the sets of grooves 411, to cut a thread in the pipe which is located in the respective aligned bores C and Pa. The sets of chasers can thus operate on respective pipes of the same diameter, or on pipes of In using the multiple diestock, a pipe is inserted through one of the bores C and the respective aligned bore Pa, and the chips fall out of the unobstructed bores.

Fig. also illustrates the conventional operating handles H for turning the multiple diestock. The top plate which is used in the embodiment of Fig. 5 is identical with that shown in Figs. 1 and 2.

The device has been illustrated in a position in which its longitudinal axis is vertical, but of course said longitudinal axis can be in any position.

When the diestock is assembled, each clamping screw 8 is located wholly laterally relative to the respective chaser 5, save that a part of the head of each clamping screw 8 overlaps the top wall of the respective lug or projection I I. This overlapping is not necessary. The bottom planar walls of the recesses I2, with the exception of the bottom walls of extension I4, fit snugly against the planar top edges of the chasers, save for the radially projecting portions of said chasers. When the plate 9 is in clamping position, there is a slight clearance between the bottom planar wall of said plate, and the planar top walls of the posts 3. This clearance is so slight that it is not shown in Fig. 1. A part of the representation of the top plate 9 has been broken away in Fig. 1 in order to show the construction more clearly. When the device is assembled, the butt end of each chaser 5 is spaced radially inwardly from the outer radial end of the respective groove 4. The butt end of each chaser has a planar edge, and its top and bottom edges and its side edges are also planar, save that the conventional undercut 5a may be provided, if desired. This is an additional feature and advantage of the invention because of the great simplicity of the shape of each chaser.

The body of each type of diestock is of the usual hollow construction.

For convenience, the part of the body I in which the radial grooves 4 are located, is designated as the peripheral body portion, even though said peripheral body portion consists of a series of separated posts or members. This peripheral body-portion has a free planar face, which is the top face in Figs. 4 and 5. The toothed part of each chaser is designated as being located at the radial inner end thereof. It is preferred to have each chaser to fit throughout as closely as possible in the respective radial groove 4 and radial recess I2, but it is sufiicient if parts of each chaser abut the walls of thev respective radial groove 4 and radial recess I2, so that the screws B and the clamping plate 9 can hold the chasers fixed relative to the body I. Each chaser extends abov the peripheral body portion and its radial grooves It, into the respective superposed radial recess I2. Each recess I2 is open at its radial inner end and it has an end-wall at its radial outer end, The bottom of said end-wall is flush with the bottom surface of the plate 9.

The end-wall of each recess I2 is located radially inwardly relative to the outer radial end of the respective chaser-receiving groove 4. The fastening plate wholly clears the chaser-receiving grooves 4 and the outlet grooves 6.

While it is preferable to have the top portions of the chasers fit snugly in the respective parts of the radial recesses I2, the invention is not limited to this feature, as long as the bottom walls of the recesses I2 exert the necessary clamping pressure;

For convenience, the device is described in the claims with reference to the vertical position shown in Figs. 1 and 5, although the devicecan be used in any position.

I have shown preferred embodiments of my invention, but it is clear that numerous changes and omissions can be made without departin from its spirit.

I claim:

1. A diestock having a hollow body which is provided with a peripheral body portion which has a free top face, said body having a longitudinal axis around which said body is turned when the diestock is operated, said peripheral body portion having a plurality of spaced up- 1 standing posts which are axially slotted to provide chaser-receiving grooves which are radially disposed relative to said longitudinal'axis and whose walls extend upwardly from the top of said free face, a chaser located in each said chaser-receiving groove, each chaser extending radially inwardly of its respective groove and having teeth at its radial inner end, the upstanding radial walls of the respective chaser-receiving groove, spectively abutting the respective corresponding walls of the respective chaser receiving groove, each chaser extending above its said groove, a fastening plate which has a central opening, said fastening plate having upstanding lugs which are located wholly above the tops of said grooves, each said lug having a recess which is aligned with and which is located directly and wholly above one of said chaser-receiving grooves, each said recess being open at its radial inner end and having an end-wall at its radial outer end, the bottom of each said end-wall being substantially flush with the bottom wall of said fastening plate, the bottom wall of each recess abutting the respective part of the top edge of the respective chaser, the upper edge of the butt-end of each chaser abutting said end-wall of the respective recess, pressure means holding said fastening plate fixed to the body and exerting clamping pressure between the bottom walls of the recesses and the top edges of the chasers so that said fastening plate clamps each chaser relative to said body and to said plate.

2. A device according to claim 1, in which said fastening plate is of stamped construction.

3. A diestock having a hollow body which is provided with a peripheral body portion which has a free face, said body having a longitudinal axis around which said body is turned when the diestock is operated, said peripheral body portion having a plurality of spaced upstanding posts which are axially slotted to provide chaserreceiving grooves which are radially disposed relative to said longitudinal axis and whose walls extend upwardly from the top of said free face, a chaser located in each said chaser-receiving groove, eachchaser extending radially inwardly of its respective groove and having teeth at its radial inner end, the upstanding planar radial walls and the planar bottom edge of each chaser respectively abutting the respective corresponding walls of the respective chaser-receiving groove, each chaser having a planar top edge, each chaser extending above the top of its chaserreceiving groove, a fastening plate which has a central opening, said fastening plate havin lugs which are located wholl} above the tops of the respective grooves, each said lug having a recess which is aligned with and which is located directly and wholly above one of said chaser-receiving grooves, each said recess having radial walls, each said recess being open at its radial inner end and having an end-wall at its radial outer end, the upstanding radial walls of each chaser having top portions which abut the radial walls of the respective recess, a part of the buttend of each chaser abutting the end-wall of the respective recess, the bottom walls of said recesses being substantially planar and abutting the planar top edges of the chasers, pressure means holding said fastening plate fixed to the body and clamping the bottom edges of said recesses against the top edges of the chasers, said end-walls of said recesses being located radially inwardly relative to the outer radial ends f said chaser-receiving grooves.

4. A 'diestock having a hollow body which is provided with a peripheral body portion which has a free face, said body havin a longitudinal axis around which said body is turned when the diestock is operated, sai peripheral body portion having a plurality of chaser-receiving grooves which are radially disposed relative to said longitudinal axis and which extend axially inwardly from said free face, a chaser located in each said chaser-receivin groove, each chaser extending radially inwardly of its respective groove and having teeth at its radial inner end, the radial Walls and the bottom edge of each chaser abutting the respective corresponding walls of the respective chaser-receiving groove, each chaser extending above its chaser-receiving groove, a fastening plate which has a central opening, said fastening plate having lugs which are located wholly above the tops of the respective grooves, each said lug having a recess which is aligned with one of said chaser-receiving grooves, each said recess having radial walls, each said recess being open at its radial inner end and having an end-wall at its radial outer end, the radial walls of each chaser having portions which abut the radial walls of the respective recess, a part of the butt end of each chaser abutting the end-wall of the respective recess, clamping screws holdin said fastening plate fixed to the body and clamping the bottom edges of said recesses against the top edges of the chasers, said end- Walls of said recesses being located radially in wardly relative to the outer radial ends of said chaser-receiving grooves, each said recess having a lateral extension whose wall is spaced wholly from the respective chaser, the walls of said lateral extensions having axial bores which are aligned with respective axial tapped bores of said peripheral body-portion, said clamping screws having shanks which engage the walls of said tapped bores.

5. A diestock which has a hollow body portion, said body portion having a longitudinal axis around which said body is turned when the diestock is operated, said body having spaced projections which extend axially of said body portion, chaser-receiving grooves associated with said pro- Jections which are radially disposed relative to said axis, a chaser located in each said chaserreceiving groove, each chaser extending radially inwardly of its respective chaser-receiving groove, each chaser having teeth at its inner end, each chaser having radially disposed side walls which abut the radially disposed side walls of the respective chaser-receiving groove, each chaser also having a bottom edge which abuts the bottom wall of the respective chaser-receiving groove, each chaser extending above its respective chaser-receiving groove, a fastening plate which has a central opening, said fastening plate having upstanding lugs which are located wholly above the tops of said grooves, each said lug having a recess which is aligned with and which is located directly and wholly above one of said grooves, each said recess being open at its radial inner end and havin an end-wall at its radial outer end, the bottom of each said end-wall being substantially flush with the bottom wall of said fastening plate, the bottom wall of each said recess abutting the respective part of the top edge of the respective chaser, the upper edge-part of the butt-end of each chaser abutting said end wall of the respective recess, pressure means holding said fastening plate fixed to said body portion and exerting clamping pressure between said bottom walls and said top edges of said chasers so that said fastening plate clamps each chaser relative to said body portion and relative to said plate.

JOHN E. WALDO. 

